Abstract
Vacuum kinetic spray (VKS) technology was employed to fabricate AlN films. In order to investigate the relationship between the deposition behavior with change of the size and microstructure of feedstock, AlN powders were pre-treated through ball-milling and heat-treatment. It is observed that the particle size decreased and defect density increased after the ball-milling. After the heat-treatment of the ball-milled powder, on the other hand, the particle size was not changed significantly, while the defect density was reduced by recovery. The coatings of ball-milled and heat-treated powder were obviously thicker than that of only ball-milled powder. It is inferred that, during the heat-treatment, although the defects were reduced by recovery, the dislocations were aligned, through which the cracks were able to propagate more easily. By the combined effects of ball-milling and heat-treatment, more fragmentations with new surfaces of the particles were generated during VKS, which would improve the deposition efficiency. Therefore, in VKS process, the deposition behavior is shown to be affected by not only particle size, but also the defect density and microstructure of the feedstock powder.
